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VEGETABLE GARDENING 
367. Club root (Plasmodiophora brassicac) , also known 
as “club foot” and “clump foot,” is unquestionably the 
most serious disease of crucifers. (Figure 72.) If un- 
controlled it will soon spread through a community and 
render the profitable cultivation of cabbage and allied 
plants impossible for several years, a situation that 
has developed in a few sections of the United States. 
The malady has been known in Europe for more than a 
century and in this country for many years. 
The disease is most destruc- 
tive to cabbage and turnip, but 
also affects cauliflower, brussels 
sprouts, kale, radish, kohl-rabi, 
rutabaga, white mustard and 
many cruciferous weeds, shep- 
herd’s purse and hedge mustard 
being especially subject to in- 
fection. 
The character of the disease 
and its relation to “clubbing” 
were determined by the Russian 
botanist, Woronin, who found 
that the micro-organism which 
causes the distorted enlarge- 
fjg. 72. club root of nient of roots was a slime mold 
cabbage and not a bacterium nor a lun- 
gus. There is distinct “club- 
bing” in many cases, while in others irregular knots are 
formed. When the disease has advanced for several 
weeks, tuc deformed roots are incapable of supplying the 
plants with sufficient moisture and nourishment. The 
plants then become dwarfed and lighter in color. 
Affected plants wilt quickly in warm, sunny weather, 
especially if preceded by humid growing weather. The 
disease is less serious with the early than with the late 
crop, for with the best conditions for growth at this 
